Skip to Main Content
Skip Nav Destination

Keatite; II, Hydrothermal synthesis from silica-glass

Brigitte Martin
Keatite; II, Hydrothermal synthesis from silica-glass
European Journal of Mineralogy (December 1995) 7 (6): 1389-1397


The metastable, microcrystalline silica phase k has been synthesized from solid silica-glass rods and from granular high-purity (SiO (sub 2) 99.99 wt.%) silica-glass at 400 degrees C, 350 bars with a run time of 1-2 days in 0.01 N NaOH/H (sub 2) O solution. Variations in Na (super +) concentration in the solution lead to the growth sequence quartz-fibrous keatite-disordered cristobalite C. Keatite coexists with quartz and/or cristobalite, with sharp microstructural boundaries. As the Na (super +) is incorporated in keatite, the pH of the solution changes from 12 to 9, and in this less alkaline solution keatite transforms to quartz in a few hours, accounting for the low yield under hydrothermal conditions.

ISSN: 0935-1221
Serial Title: European Journal of Mineralogy
Serial Volume: 7
Serial Issue: 6
Title: Keatite; II, Hydrothermal synthesis from silica-glass
Author(s): Martin, Brigitte
Affiliation: Ruhr-Universitaet Bochum, Institut fuer Mineralogie, Bochum, Federal Republic of Germany
Pages: 1389-1397
Published: 199512
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Federal Republic of Germany
References: 16
Accession Number: 1996-014812
Categories: Mineralogy of silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table, 5 plates
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United KingdomTwickenhamUKUnited Kingdom
Update Code: 199606
Close Modal

or Create an Account

Close Modal
Close Modal